原文：http://blog.chinaunix.net/space.php?uid=9398085&do=blog&id=1677464
哈希结构
%movies = ('The Shining'=> 'Kubrick', 'Ten Comandments' =>'DeMille','Goonies' =>'Spielberg');
print $movies{'The Shining'};
其中‘The Shining’是关键字，'Kubrick'是值
打印哈希结构中的每个关键字
foreach $film (keys %movies){
print "$film\n";
}
输出为：
Ten Comandments
Goonies
The Shining
利用keys和values得到关键字和值
@directors=values %movies;
@film=keys %movies;
print "@directors\n";
print "@film\n";
输出为：
DeMille Spielberg Kubrick
Ten Comandments Goonies The Shining]
拷贝和组合
%New_hash=%Old_hash;
%Both=(%first,%second); #组合后将随机排列
利用函数exists测试是否存在某个关键字
if (exists $movies{conan}){ # movies中是否存在conan这个关键字
print "exist!" ;
}
删除某个关键字
delete $both{conan};
寻找数组中的唯一元素
@fishwords=qw(one fish two fish red fish blue fish);
%seen=();
foreach (@fishwords){
$seen{$_}=1;
}
@uniquewords=keys %seen;
print "@uniquewords";
输出为：blue one red two fish
寻找两个数组间的不同部分和交汇部分
@stars=qw(R.Reagan C.Eastwood M.Jackson Cher S.Bono);
@pols=qw(N.Gingrich S.Thurmon R.Reagan S.Bono C.Eastwood M.Thatcher);
%seen=();
foreach (@stars){
$seen{$_}=1; #对电影明星的列表进行迭代操作，依次将$设置为每个名字
}
@intersection=grep($seen{$_},@pols); #@pols中的grep函数对政治家的列表进行迭代操作，依次将$_设置给每个政治家。然后，在哈希结构%seen中寻找该名字
print "@intersection";
输出为：R.Reagan S.Bono C.Eastwood
需找两个数组中的不同部分
@difference=grep(! $seen{$_},@pols);
输出为：N.Gingrich S.Thurmon M.Thatcher ,即不是明星的所有政治家
读入txt文件，并按输入的关键字输出customer信息
#!/usr/bin/perl -w
open(PH,"C:/Documents and Settings/Administrator/桌面/customers.txt") or die "Cannot open customers.txt: $!\n";
while(<PH>){ #文件句柄被读取，每一行被赋予$_
chomp;
($number,$email)=(split(/\s+/,$_)) [1,2]; # $_中的这一行在空格处被分割,只取前两项
$Phone{$number}=$_; #将每一行存入一个哈希结构，key为number，value为一条记录
$Email{$email}=$_;
}
close(PH);
print "Type 'q' to exit\n";
while (1){
print "\nNumber?";
$number=<stdin>;chomp($number);
$address="";
if(!$number){
print "E-mail?";
$address=<stdin>;chomp($address);
}
next if(!$number and !$address);
last if($number eq 'q' or $address eq 'q');
if ($number and exists $Phone{$number}) {
print "Customer: $Phone{$number}\n"; #输出关键字为number的值
next;
}
if ($address and exists $Email{$address}){
print "Customer: $Email{$address}\n";
next;
}
print "Customer record not found.\n";
next;
}
print "\nAll done.\n";
统计单词出现的频度
open(FH,"C:/Documents and Settings/Administrator/桌面/test.txt") or die "cannot open test: $!";
while(<FH>){ #每次读取一行标准输入，为每一行设置$_
while(/(\w[\w-]*)/g){ #以文件中的空格分隔成单词。对$_中的每个单词进行迭代操作
$words{$1}++;
}
}
foreach (keys %words){
print "$_ $words{$_}\n"; #输出每个单词的频度
}
输出为：
peach 2
banana 1
apple 2
orange 2
pear 1
统计单词的长度
open(FH,"C:/Documents and Settings/Administrator/×ÀÃæ/test.txt") or die "cannot open test: $!";
while(<FH>){ #每次读取一行，为每一行设置$_
while(/(\w[\w-]*)/g){ #以文件中的空格分隔成单词。对$_中的每个单词进行迭代操作
$seen{length $1}++; #以单词的长度为关键字
}
}
foreach (keys %seen){
print "There are $seen{$_} words have $_ letter(s). \n"; #输出关键字和值
}
输出为：
There are 3 words have 6 letter(s).
There are 1 words have 4 letter(s).
There are 4 words have 5 letter(s).